City Spiders Are Bigger, Fatter, And More Fertile

Researchers from the University of Sydney found that members of the orb-weaving species Nephila plumipes grew larger, fatter, and reproduced faster when they lived in urbanized city environments instead of their natural wild habitats.

Writing in PLOS ONE, the authors (headed by doctoral candidate and spider-lover Elizabeth "Lizzie" Lowe) speculate that city-spiders have two major factors in their favor:

  1. The metropolitan "heat island effect," which can raise city temperatures as much as 12° C (22° F) at certain times of the day, helping spiders grow faster and be active for more hours each day and more days out of the year, and
  2. An abundance of artificial lighting, which acts like all-night insect magnets . . . providing N. plumipes a great place to build its web to score lots of extra food without any extra effort.

N. plumipes can finally be counted among the successful "urban exploiters," such as the hooded crow, the house sparrow, and the Norwegian rat. You can read the full study (which has zero spider photos in it) for free on PLOS ONE.


Urbanisation at Multiple Scales Is Associated with Larger Size and Higher Fecundity of an Orb-Weaving Spider. PLOS ONE. DOI: 10.1371/journal.pone.0105480

Photo Credit: Gnissah/Wikimedia Commons. Licensed under Creative Commons Attribution-Share Alike 3.0.

I cropped the spider out of the original picture. You're welcome.